Support was strongest amongst young voters; with 81 per cent of respondents aged 18-24 supporting same-sex marriage.

Only a slight majority of older voters support legal reform, with 51 per cent of respondents aged 50-64 supporting a change to allow gay couples to marry.

Respondents were also surveyed about whether an exemption for churches from having to marry same-sex couples would effect their feelings on the issue.

Twenty-eight per cent of people said they were 'more willing' to agree to support same-sex couples being allowed to marry if churches could refuse to do so, while 17 per cent said they were less willing to agree.

Two private members bills supporting changes to the Marriage Act were due to be introduced to parliament today, one co-sponsored by Greens MP Adam Bandt and Independent Andrew Wilke, the other by Labor backbencher Stephen Jones.

Mr Bandt told parliament he believed the power of love would eventually conquer all and predicted same-sex marriage would be legalised in Australia before the end of the year as he introduced his bill this morning.

"I believe it is love that has brought us to this place in this debate and it is love that will carry us over the threshold of discrimination to full marriage equality," he said.

Labor MPs will be allowed a conscience vote on the issue.

Federal opposition leader Tony Abbott had ruled out a conscience vote amongst Coalition MPs but a report in The Australian newspaper this morning suggested he may allow one among backbenchers.

Another bill seeking to legalise same-sex marriage, introduced by Greens senator Sarah Hanson-Young in 2010, is in front of a Senate inquiry.

Hodson's daughter: Witness protection not safe

"I feel sorry for anyone coming into witness protection," says the tearful daughter of police informer Terence Hodson after the State Coroner delivered an open finding into his murder and that of his wife Christine in 2004.